Lamp hanger with multiple contacts



' T. B.FARRINGTON 9 LAMP HANGER WITH MULTIPLE CONTACTS Fil ed May 1, 1940 3 Sheets-Sheet 2 27b 9 I IP 270. 9 a D 2 3 HI 26 .114 L 'L-- INVENTOR FIG-2 THAYER B. FARRINGTON ATTORNEYS 1 9 T. B FARRINGTON 2,

' LAMP HANGER WITH MULTIPLE CONTACTS Filed May 1, 1940 s Sheets-Sheet 3 INVENTOR THAYER B. FARRINGTON ATTORNEYEJ FIG-l2 Patented July 14, 1942 UNETED STATES PATENT GFFICE 8 Claims.

This invention relates to a lamp hanger for providing a plurality of separable electric connections, more than two, for supplying current to an electric fixture which is arranged to be latched in a raised position or lowered for purposes of repair, maintenance and the like.

The present invention provides a novel structure for providing a plurality of separable electric contacts, together with means for equalizing the contact pressure between the coacting pairs of contact members when the separable parts are engaged as occurs normally whenever the electrical fixture is in use. The novel features of the invention will be apparent from the accompanying drawings and specification and the essential features thereof will be set forth in the claims.

In the drawings, Fig. 1 is a central sectional view taken along the line l| of Fig. 2 and showing one embodiment of my invention; Fig.

2 is an enlarged transverse sectional view taken along the line 22 of Fig. 1; Fig. 3' is an elevational View of one of the upper contact members taken at right angles to the view shown in Fig.

1; Fig. 4 is a bottom plan view of the structure of Fig. 3; Fig. 5 is an end elevational view of one of the bottom contact members and support therefor of Fig. 1; Fig. 6 is a top plan vieW- of the structure of Fig. 5; Fig. 7 is a bottom plan view of the-structure of Fig. 5 taken from approximately the position indicated at 11 on Fig. 5; Fig. 8 is a sectional view taken along the line 88 of Fig. 5; Fig. 9 is a. sectional View taken along the line 9-9 of Fig. 6; Fig. 10 is a view similar to Fig. 8 showing a modification in which i the equalizer bar is in a different position; Fig. 11 is a view similar to Fig. 9 showing a modification as to another detail; Fig. 12 is a view similar to Fig. 2 showing an arrangement providing three pairs of contacts; while Fig. 13 is a-view showing still another modification providing for six pairs of contacts,

My invention relates to improvements in lamp hanger structures adapted for supporting lamps in elevated position and for lowering the same for repairs and maintenance. The present inventionis directed to the provision of a plurality of electrical contacts in such lamp supporting structures. One place where such an invention is useful is where standard incandescent lamps and mercury lamps are supported in the same fixture. In such a case different voltage is necessary for the two lamps and a plurality ofcontacts is necessary. Four contacts may be used.

two for each voltage or sometimes three contacts 55 may be used if an auto-transformer is provided. Other uses for my improved multiple contact'devices will readily occur to those skilled in this art.

The structure shown in the present embodiment comprises "a main lamp hanger member 10' generally mounted in a fixed position at some elevated point in a building or on a structure of any sort; preferably by means of a combined bracket and sheave housing H through which the chain or cable for manipulation of the lowering hanger member is conducted away to some remote point. The mainhanger member comprises a tubular guide ['3 rigidly secured to the main hanger member and having a hollow central portion for receiving and embracing the guide stem 14 of the lowering hanger member 15. The stem M has afin Ma which enters a slot [3a in the tubular guide, being guided to that position by the cam surface It. The latch I1 holds the stem M in position latched to the guide l3 as is more fully described in my 00- pending application Serial No. 298,982, filed October 11, 19391 The main hanger member has secured to it two blocks l8 of insulating material. Qne ofthe'se blocks is shown in elevation in Fig. '3 and in bottom plan view in Fig; 4. Suitably mounted in these blocks is a pair of contacts [9 which may be secured to the block as by means of the bolts 26a. It will be noted that'the contacts l9 are of cup-shape form opening downwardly to coact with the movable contacts. Preferably a flange or shoulder Ilia of insulating material extends downwardly between the two contacts [9 on each of the blocks I8 so as to electrically shield the contacts from each other. A recess 20 extends laterally away from each contact l9 to permit the attachment of wires 2| to the contacts [9. It will be understood that these wires 2| enter the enclosing canopy 22 either through the top or side wall thereof and are'connected to the electrical system.

The lowering hanger member l5 comprises a spring housing 23' surrounding the stem It; the two parts being yieldably connected by means of a spring 24 which is compressed between a flange l lb on the stem I l and a flange [Ed on the housing 23. It will be noted in Fig. 1 that the stem M is'hollow so as to accommodate the lowering chain or cable 25 which is suitably secured within the stem Hi and normally passes out through the sheave housing ll and downwardly to a point within easy reach of. an operator. The resilient connection provided by the spring 24 permits a raising of stem I l and the hanger member l above the position of Fig. 1 in order to disengage the latch I! so as to permit lowering of the movable hanger member. The spring 24 also permits sufificient tilting movement between stem l4 and housing 23 to equalize pressure between the contacts carried by the leftand right-hand arms [5b of Fig. 1. Formed as a portion of the member l5 are the laterally extending brackets I52) which support the lower or movable electrical contact members.

These lower contact members ar preferably supported in pairs in a manner to permit relative vertical movement between the two members 23 of a pair so that they may fully engage the coacting pair of contacts I9. To this end each contact 26 may be mounted in a separate insulating block as shown in Figs. 5 to 9 or the contacts may be in one block a shown in Fig. 11

with a flexible portion between the contacts.

Referring particularly to Figs. 5 to 9, one of the lower contact members is shown at 26 secured to a block of insulating material 21 by means of a screw 28. A strip of electrical conducting ma terial 29 molded in the block 27 passes from a point above the bracket I5b to a point therebeneath where it is provided with a binding post 30. Referring to Fig. 6, it will be noted that the top of the block 21 is provided with a recess 21a opening outwardly to one side providing a pocket sufiicient to accommodate the coacting contact I 9. It will be noted that this recess leaves a wall 21b on each block 2! which serves to shield the contacts 26 from each other. Referring to Figs. 5 and 6 it will be noted that a pair of blocks 21 coact to provide a recess 3| for the accommodation of the projection l3a of the upper contact carrying block [8. Thus when a pair of contacts I9 and 26 are in engagement each pair of contacts is housed on three sides by the insulating material so that they are electrically completely separated from each other. Referring especially to Figs. 1, 5 and 7, it will be noted that the blocks 2! at their lower ends are provided with recesses 21c permitting the easy introduction of wires 32 to the binding posts 30. Here again the material of the blocks 21 surrounds th binding posts 30 on three sides so that they are electrically separated from each other. It will be understood by those skilled in this art that the wires 32 lead inwardly through openings 33 in an adapter 34 and thence extend downwardly to electrical fixtures.

It will be noted that each block 21 has a centrally located narrow portion 21d intermediate it ends at the point where the block passes through th bracket lEb. This bracket has a semicircular recess opening outwardly and the portions 21d of a pair of blocks 21 together form a substantially cylindrical shaft which i fairly snugly embraced by the semicircular recess 35 in the bracket 15b. Means is provided for holding the blocks 21 in the recess 35. The means here provided comprises a keeper bar 36 having bifurcated ends 36a which embrace th bracket portion I5b to which they are secured as by means of cotter pins 31. The blocks 21 are prevented from turning when locked in position by the keeper bar 36 by reason of the arcuate side face portion 38 which as shown in Fig. 7 closely approach the housing 23. By making similar arcuate faces at 38a the blocks 21 are identical.

As mentioned above, the spring 24 and the arrangement of the parts permits a relative tilting movement of the lowering hanger member with respect to the main hanger member so that the pair of contacts seen at the left in Fig. 1 and the pair of contacts seen at the right in the same view have their contact pressure equalized when the hanger members approach each other and are latched together. This tilting occur in a plane generally parallel to the sheet as viewed in Fig. 1. I also provide novel means for permitting equalization of contact pressure between each two pairs of coacting contact members either at the right or the left as seen in Fig. 1. To this end a single pair of contact members 26 as assembled in a single unit as viewed in Fig. 5 is permitted to oscillate in a plan at right angles to the sheet as viewed in Fig. 1. In other words the equalization of the pressure between a group of two contact members 26 on one side of the coacting guiding parts l3, I4 is in a plane generally at right angles to a plane generally represented by the line l-I of Fig. 2. A special form of equalizer bar 39 is provided for this purpose. This bar is generally of H-like form as best seen in Figs. 8 and 9 and comprises a central cross bar 39a, which is embraced between a pair of blocks 21, and end bars 392) which underlie the upper portions of the blocks 21. To this end the upper surface of each bar 39 is generally plane and the blocks 21 have plane surfaces Zle where they rest upon the upper face of the bar 39. As best seen in Fig. 9, the blocks 21 are recessed at 40 so as to embrace the cross bar 39a. Thus when a pair of blocks 21 are assembled in the bracket 15b and held by a keeper bar 36, the equalizer bar 39 is held in position. To permit a tilting action of the equalizer bar 39, it is provided with a downwardly extending knife edge 4| running longitudinally of the cross bar 39a and resting as shown in Fig. 1 at one end upon the keeper bar 36 and at the other end upon the bracket portion l5b. These coacting portions which engage the knife edge 4| are arranged at the same level for this purpose. Obviously when the pair of lower contacts 26, as viewed in Fig. 5, approach a pair of upper contacts I9, as shown in Fig. 3, the bar 39 permits oscillation of the movable contact members so as to equalize contact pressure between the two pairs of coacting contact members. Clearance between the parts at this time permits alinement of coacting contacts. All of th contact members on the coacting hanger members are resiliently held in engagement by th spring 24 when the parts are in latched position as viewed in Fig. 1.

The bar 39 of Fig, 11 may be a straight bar with little or no end pieces as would be necessary with such a construction. One or more pins 42 may be provided to prevent the bar moving endwise. It will be understood that bridge 43 i flexible enough to permit relative vertical movement between the two contacts 26.

In Fig. 10 I have shown a modification which will be readily understood upon reference to Fig. 8. It will be recalled that in the form shown in Fig. 8 the tilting or oscillation of the two contacts 26 forming a single group occurred in a plane at right angles to the tilting of the parts l4 and 23 relative to each other. In the modification of Fig. 10 the structure is in all respects similar except that the H-like bar 39 has been turned from the position shown in Fig. 8. Here as before the construction permits a tilting of the blocks 2'! and their associated contacts 26 but the tilting occurs in approximately the same plane as the tilting between the parts [4 and 23.

If necessary, the blocks l8 carrying the contacts I9 could be turned 90 from the position of Fig. 1.

If necessary or desirable the device would obviously work equally well if, for instance, two pairs of coacting contact members as have just been described were provided on the left-hand side of Fig. 1 while a single pair of coacting contact members I9, 26 were provided at the righthand side thereof. This arrangement is shown in Fig. 12. The single contact shown at the right is similar to that shown in my abovenamed copending application. In such a case the relative tilting between the parts 23 and M would permit equalization between the leftand right-hand sides while the equalizer bar 39 on the left-hand side would permit equalization between the two contacts located there.

In Fig. 13 I have shown a modification which provides for six pairs of contacts. In this form the hanger member I is provided with three bracket portions l5b extending outwardly from the main housing 23. Each of these bracket portions supports a pair of contacts 26 in the manner described in connection with the first form hereinabove mentioned. All of the other parts are exactly as described in connection with the first form, it being understood of course that six fixed contacts is are provided on the hanger member In instead of the four contacts disclosed in connection with the first form. As the lowering hanger member approaches the main hanger member there will first be a three-point equalization between the parts carried by the three bracket portions 151). The final equalization will occur between each pair of contacts supported by one of the equalizer bars 39. The canopy should house all of the contacts and is here shown circular.

If the teaching of Fig, 12 is applied to Fig. 13 any number of pairs of contacts between 3 and 6 may be provided.

What I claim is:

1. Electrical contact supporting means comprising a bracket providing a recess open at one side, a keeper bar for closing the open side of said recess, a pair of insulator blocks adapted to be embraced and held by said bracket recess and said keeper bar, electrical contacts mounted one on each block, rigid bar means held between said blocks and supporting each block, said bar means having a downwardly extending knife edge extending normal to a plane passing through said contacts, and said knife edge having one end resting upon said keeper bar and having its other end resting upon said bracket.

2. The combination of claim 1 wherein said bar means is of H-like form, and said knife edge extends along the central cross-bar thereof.

3. In a lamp hanger structure having coacting separable and lowering hanger members having interfitting centrally located guiding parts adapted to coact when said members engage, the com bination of three arms on said lowering hanger member spaced circumferentially about said guiding parts, a pair of contact members on each of said arms, coacting pairs of contact members on said main hanger member, and equalizer bar means for equalizing the engaging pressure of the pair of contact members on each arm.

4. Electrical contact supporting means comprising a bracket providing a recessed opening, a pair of insulator blocks in said recess, an electrical contact on each block, a keeper bar connected with said bracket and engaging said blocks and holding said blocks in said recess, and equalizer bar means providing a pivotal support for said blocks located between said blocks and permitting oscillation of said blocks about said pivotal support, whereby to equalize pressure on said contacts when they are moved to a position engaging other contacts.

5. Electric contact supporting means comprising pivot means, a pair of insulator blocks on opposite sides of said pivot means and supported thereby, an electrical contact on each block, and flexible means connecting said blocks and permitting relative vertical movement between them, whereby to equalize pressure on said contacts when they are moved to a position engaging other contacts.

6. In lamp hanger structure comprising a bracket having a plurality of recessed openings each adapted to receive a contact-carrying unit, and having a keeper bar connected with said bracket at each recess, each bar engaging its associated unit and holding said unit in its recess, the combination of a two-block contact unit having two insulator blocks adapted as a unit to be held in one of said recesses by one of said bars, an electrical contact on each of said last named blocks, and equalizing means carried by said unit for providing relative vertical movement between said contacts on said two-block unit.

'7. Electrical contact supporting means comprising a bracket having a recessed opening, a pair of insulator blocks adapted when placed adjacent each other as a pair to fit in said recess, an electrical contact on each block, a keeper bar connected with said bracket and engaging said blocks and firmly holding them in said recess, equalizer bar means providing a pivotal support for said blocks located between said blocks and permittting oscillation of said blocks about said pivotal support, whereby to equalize pressure on said contacts when they are moved to a position engaging other contacts, and there being recesses in adjacent faces of said insulator blocks which, when said blocks are placed together in a pair, embrace and hold said equalizer bar means.

8. Electrical contact supporting means comprising bracket means providing an opening, a pair of insulator blocks in said opening, said bracket means cooperating with said blocks to hold the latter in said opening, an electrical contact on each block, and equalizer bar means providing a pivotal support for said blocks located in a plane between said blocks and permitting oscillation of said blocks about said pivotal support, whereby to equalize pressure on said contacts when they are moved to a position engaging other contacts.

THAYER B. FARRINGTON. 

